Local festivals, particularly in summer months, may also include castellers, a relatively serious event where young men and women in traditional costume (xiquets) form human towers to the strains of an orchestra (the cobla), which announces with strange but often engaging music, the different steps in the building process. This extraordinary Catalan speciality, usually held in the plaza in front of the mayor´s office (ajuntament) is frought with danger for its participants. Performers deftly climb onto one another´s shoulders to form a human pyramid (casteller). The better of the colles (performing groups) build varying structures as much as nine or 10 stories high, topped by a small boy or girl called (enxaneta) or the weathercock. How they all don´t get injured when the castells collapses - as castells often do - is a mystery. This is really a must-see event. You'll never forget it!